In 1937, Napoleon Hill wrote Think and Grow Rich.  In the book, Hill wrote about the value of masterminds.

All mastermind is, is a group of people that get together and share and collaborate for an express purpose of getting better.

In educational terms there are a lot of similarities between a mastermind and a community of practice.  In his book Workplace Learning, Principles and Practice, Robert W. Rowden suggests the following: